High strength, metallic nets have been deployed defensively against submarine attacks for several years. The nets may be paid out from a vessel, as shown in U.S. Pat. No. 2,383,095, granted to D. A. Wallace, or may be stretched across the depth and width of a narrow body of water, and anchored to the floor of the body of water, as shown in U.S. Pat. No. 2,170,481, granted to J. J. Morrison et al. Diverse other defensive nets are disclosed in the prior art--see, for example, U.S. Pat. No. 2,388,459, granted to C. S. Allen, Jr.
Known metallic nets, however, are costly to manufacture, and have proven difficult to store on board a sea-going vessel because of their significant weight and bulk. Also, when known metallic nets are paid overboard from a platform on the vessel, the vessel is subjected to considerable drag and must operate at reduced speeds. The time required to deploy these nets is measured in hours or days. Conventional nets are essentially static in operation, and are either fixed to the ocean floor or to the floor of a smaller body of water, or dragged slowly through the water adjacent a large vessel, such as a battleship. In either case, known nets are defensive in character, and have proven ineffective against the new generations of deep ranging, mobile, high speed, nuclear powered submarines as well as against maneuverable surface vessels. Furthermore, known nets are readily detected by radar and sonar such that evasive actions can be undertaken to defeat such nets.